1. Field of the Invention
The present invention relates to apparatus and a method for removing liquid from sludge and, more particularly, to an apparatus and method for removing liquid from sludge that prevents the liquid extracted from the sludge from being reabsorbed by the sludge as it travels through the apparatus.
2. Description of the Prior Art
Machines that remove liquid from sludge in the process of disposing of the sludge have existed for some time. One machine is manufactured and marketed by the assignee of the present application under the name "Roediger Belt Filter Press" (hereinafter referred to as the "BFP"). The BFP employs dual belts that are designed to support sludge and move it through the BFP over a series of rollers. The belts are maintained under tension and cooperate with the rollers to compress the sludge and extract liquid from it. Although the BFP is highly effective in removing liquid from sludge, it suffers from the problem that the roller placement allows extracted water to be deposited on portions of the belts which are not in contact with the roller and, therefore, are not compressing the sludge. The extracted liquid is reabsorbed by sludge which was already partially deliquified, negating, to an extent, the deliquification which already had occurred.
To avoid the problem described above, the positioning of the rollers of the preferred embodiment of the present invention allows deflectors to be mounted below each roller to deflect extracted liquid from uncompressed sludge. The roller positioning, preferably, causes the belts to follow a generally vertically projecting undulating pattern, although other arrangements are equally functional. Such deflector placement is not possible with existing sludge deliquification machines due to the positioning of the rollers in those machines.